Every point in a scatterplot represents one person or object, and the coordinates of that point are the values of the X and Y variables. As an example, the following graphic shows the scatterplot and some of the data for the relationship between Life Expectancy and Per Capita Expenditure for Medical Care.
Austria 70.90 810.00
Denmark 71.40 880.00
Canada 71.00 920.00
Norway 72.20 920.00Notice that Austria has a life expectancy of 70.90 years and spends $810 per capita on medical care. Thus the coordinates of its points are 810 for X and 6770.9for Y. In the figure you can see how these coordinates lead to a specific point for Austria.
David C. Howell
7/4/2006
